is there something wrong with me?

my advice to you would be to sit back and ask yourself why you are doing these nice things for her. If you are truly doing it just because you are a nice guy then there is no problem with that. But you seem to think by doing these nice things you can get her back and from the sounds of it you wont be able to.

You need to realize she doesn't think of you the way you want her to and to move on. Stop being her run around boy unless you get some satisfaction from it. By focusing your energy on her you might possibly be missing the right girl.